Magnetic Resonance Imaging has been highly successful for the evaluation of many diseases of the musculoskeletal system. Unfortunately, conventional MRI has only been shown to be successful at detecting osteoarthritis (OA) in its later stages where the only available is surgical joint surface replacement (arthroplasty). The development of novel drugs that can slow or reverse the early changes of OA in cartilage has made the detection of early OA an important goal. To date, only direct observation of the cartilage via arthroscopy is useful for the diagnosis of early OA. Therefore, a noninvasive MR procedure for detecting osteoarthrits in its early stages is greatly needed. We have been studying the MR properties of human articular cartilage in order to design methods that are capable of detecting grade 1 and grade 2 osteoarthritis . The MR studies that are being performed include proton T1, T2, T1r and magnetization transfer maps, sodium spectroscopy and imaging. MR studies of cartilage before and after selective enzymatic digestion, and before and following externally supplied pressive and also being performed. All these studies are being done on bovine patellar cartilage, and grade 1 and 2 of human cartilage. Since the last progress note we have successfully dealt with two major methodologic problems that dogged our work: 1) We developed a method of ensuring that our histologic and MR sections are obtained from the same section of cartilage and 2) we have successfully implemented more sophisticated and informative staining techniques for the histologic sections of cartilage including picrosirius red for collagen and dimethylene blue for proteoglycans.